It felt a lot like a moon landing to the researchers who experienced it—descending thousands of feet below the surface of the ocean into complete darkness. Ambient ocean light extends down only about 600 feet. After that, no amount of straining your eyes will help you see through the inky blackness.

Scientist Tim Shank and photographer Luis Lamar were descending into Lydonia canyon, one of several among the canyons and underwater mountains sitting 130 miles from Massachusetts, when they were slowly surrounded by darkness.